HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF 10 HETEROCYCLIC AROMATIC-AMINES WITH ELECTROCHEMICAL DETECTION

Conditions for the HPLC-electrochemical detection determination of ten mutagenic heterocyclic amines that can be produced by heat processing of protein-rich food products were established. The use of reversed-phase chromatography and acetonitrile-ammonium acetate (10:90) at pH 4.0 for the separation of 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-6-methyldipyrido[1,2-alpha:3',2'-d]imidazole (Glu-P-1), and of acetonitrile-ammonium acetate (30:70) at pH 6.0 for the separation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-3-methyl-9H-pyrido[2,3-b]indole, 1-methyl-9H-pyrido[4,3-b]indole (harman) and 9H-pyrido[4,3-b]indole (norharman) was proposed. The figures of merit were calculated; reproducibility gave a relative standard deviation of 1.6-4.6% when measured by peak area. Detection limits (signal-to-noise ratio 2:1) ranged from 0.2 ng for Trp-P-2 to 3.4 ng for 4,8-DiMeIQx. The method was applied to the determination of some of these compounds in a commercial beef extract. Levels of 5.1 ng g(-1) MeIQx, 5.8 ng g(-1) MeIQ and 15.5 ng g(-1) of Glu-P-1 were found.